Misfire on R1100GS acompanied by no reading on oil temp RID

[Matt Padgham]

Have a probable electrical gremlin somewhere - oil temp gauge drops to show no bars followed by an engine misfire that feels as if the engine is only firing on one cylinder. Will rev and pick up but lumpy (smokey exhaust as well - unburned fuel?), after a while (anywhere from 30 secs to several minutes) the oil temp picks back up again and the engine fires normally.

Faulty HT lead? air temp sender? Oil temp sender? coil issue?

Help!!!
thanks

 

[PaulRS]

I'd say oil temp sensor, or it's wiring to the Moronic.

Easy to diagnose, remove fueltank, unplug the oil temp sensor and measure it's resistance at the plug.
It should read around 2,5 kOhms at room temp and when heating up the sensor the resistance should drop linear with no hick-ups.

The oil temp sensor is used to fine-tune fuel measurement and at cold-start to enrich the fuel mixture by making the injectors to open twice than normal.
Loss of this signal when the engine is at operating temps will send the Moronic in cold-start mode, hence the misfire and smokey exhaust.

Paul.

 

[Matt Padgham]

Thanks very much for the info PaulRS, will have to get at the sensor over the weekend.
Hoping it is as simple as that!